Ventilating system



R. F. NORRIS Sept. 12, 1939.

VENTILATING SYSTEM Filed Aug. 14, 1956 2 Sheets-Sheet 1 n vill!!! Sept. l2, 1939. R. F, NoRRls vENTILATING SYSTEM Filed Aug.. 14,V 1936 '2 Sheets-Sheet 2 "wl-:monv a/ph E /Vorr/'s ATTORNEYS F Patented Sept. 12, 1939 UNITED STATES PATENT OFFICE VENTILATING SYSTEM Application August 14, 1936, Serial No. 95,976

6 Claims.

This invention relates to improvements in ventilating systems for rooms and enclosures of all kinds including oflices, stores, restaurants, churches, auditoriums, schools, airplane cabins,

5 railway cars, motor coaches, automobiles, boats,

rooms of dwellings, etc.

It is an object of the invention to provide an improved structure for introducing air for Ventilating and for distributing it in an enclosure without drafts, such as are created by air entering from an ordinary register or grille. The structure of this invention is an improvement over that disclosed in my copending application Serial No. 62,301.

Other objects and advantages of this invention will become apparent from the reading of the following specification. In the drawings:

Fig. 1 shows a motor bus partly in section with the Ventilating treatment of my invention installed in the ceiling thereof;

Fig. 2 is an enlarged, detailed, sectional view of a portion of Fig. l;

Fig. 3 is a cross-sectional view of a modification of the Ventilating construction of Figs. l and 2 including a sound absorbing treatment;

Fig. 4 shows a railway car with my improved Ventilating system installed together with a combined acoustical treatment;

Fig. 5 is a detailed view of the construction shown in Fig. 4; and

Fig. 6 is an enlarged, sectional View of the construction shown in Fig. 4.

The motor bus of Fig. 1 is ventilated by means of a blower l whose intake is connected with an intake Agrille vl2 for outside airat the front of the bus. The bus is provided with a curved or crowned roof I8, and with a substantially at apertured member I6 which may extend across the entire width of the vehicle or may be limited to cover only the middle part. This monitor arrangement provides a space I4 between said members which I utilize as a plenum chamber. Air from the blower passes into this chamber. The apertures or openings in restriction sheetmember i are of such size and so spaced that a slight but appreciable air pressure will be present at all times .throughout the plenum chamber` I4 while the blower l0 is in operation for ventilating purposes. The cross beams 20. which may consist of any suitable structure such as T bars, have suitable openings 22 arranged in them to allow the air from the blower to be distributed throughout the length of the plenum chamber. By maintaining the necessary air pressure, al-

though small, in plenum chamber I4, the air flows from the openings in sheet I6 substantially uniformly throughout its area. The openings preferably are uniformly distributed in the sheet. A second ceiling .or sheet 24 is suspended below the first apertured sheet or restriction member and causes a still further distribution of the air into the interior of the bus. The lower apertured sheet 24 usually is closely perforated with small holes, for example, holes 0.093 inch in diameter spaced about one quarter inch apart Center to center and therefore, may be considered to be foraminous. Sheet 24 usually has a larger open area than the upper apertured sheet I6. This allows the air to be distributed without any appreciable back pressure between the two perforated sheets and prevents drafts in the interior of the bus below. The upper apertured sheet also may contain a large number of small apertures instead of a fewer number of larger openings as shown. The lower perforated sheet is more decorative because of the small area of the individual openings. These openings may be of varying size, the size being limited by the object to be accomplished. Furthermore, the regulation of the air flow may be accomplished by means of restriction sheet l5 without disturbing the lower perforate sheet and without appreciably aiecting the air flow from the lower perforate sheet in so far as uniformity of distribution is concerned. The air thus blown into the bus may be removed by means of floor registers 26 which may be connected with the inlet duct of blower l0 if desired. The air may be filtered, warmed, cooled or otherwise treated before being introduced into the plenum chamber I4.

For ordinary ventilation it is desirable` for the air below the lower foraminous ceiling to have a downward flow or velocity of one foot to ten feet per minute, though it is much higher as it passes through the holes. Lower and higher velocities may be used if desired, for example, as low as 1/2 foot to as much as 25 feet per minute, the latter being about the limit of draftless velocity. To obtain this range of air velocities it is usual to have the plenum chamber so constructed that the air pressure therein is from 0.02 inch of water to 0.100 inch of water, these representing the limits of the most desirable pressures. The pressures may range however from 0.001 to 0.300 inch of water. Under these conditions the openings in the upper apertured member should be distributed over its entire area and have a total area comprising from 0.3 to 15% of the total area thereof, the preferred range being from 1 to 5 per cent. For example, threequarters inch holes spaced every six inches on centers gaVe the desired results in one installation under the conditions previously indicated, whereas 3A, inch holes spaced every nine inches on centers were more satisfactory in another. In general the outer sheet-form member contains a large number of small apertures whereas the inner sheet-form member contains a comparatively small number of spaced-apart and distributed larger openings. Usually the total area of the larger openings is substantially smaller than the total area 'of the small openings.

The foraminous member 24 exposed to the interior of the bus may be that described in the Norris Patent No. 1,726,500 dated August 27, 1929. It may be made of perforated sheet steel, laminated wood, pressed sheet products of all kinds and other sheet-like products having the desired properties. The upper apertured member forming one wall of the plenum chamber also may be made of perforated steel, pressed sheet products of all kinds and other sheet-like materials. It also may consist of perforated soft fibrous boards, which are in themselves substantially impervious to the passage of air, whereby the holes through the boards may add to the sound absorbing efliciency of the structure. Likewise the apertured member 24 may consist of similar perforated soft fibrous boards. Whenever air-impervious is used herein it refers to a material through which air passes in such negligible amounts when the material is used as a Wall for the plenum chamber, that apertures or perforations must be made in the material in order that a sufficient volume of air will pass therethrough to provide the desired ventilation.

In the use of my construction in a railroad car, such as is illustrated in Figs. 4 to 6, the air, which is blown into the plenum chamber 28 at one end of the car, has a long path to travel under the roof 32 before it reaches the opposite end. It may be desirable to provide the inner perforated member or restriction member 30, which forms a wall of the plenum chamber 28, with a larger number of holes or openings at the end removed from the blower. This may be done by increasing the area or number of holes at the end removed from the blower. Another method of accomplishing this is by spacing the panels slightly apart as indicated at 36. Below perforated member 30 is installed the exposed perforated member 34 forming the ceiling which is visible to the passengers of the car. The crowned roof 32 and ceiling 34 likewise provide a monitor arrangement which is utilized to form the plenum chamber. The inner perforated member 3U, therefore, provides a means for changing the distribution of the air within the car without altering the outer member or without sacrificing uniformity of finish and appearance thereof. In the construction of Fig. 4, sound absorption is combined with the ceiling Ventilation as indicated in greater detail in Fig. 6. The foraminous member 30 has sound absorbing material 38 attached to its lower face by means of glue, staples, rivets or other convenient fastening means. The sound absorbing material may be any suitable material such as the blankets of shredded bers of wood sold under the trade name of balsam wool, mineral wool, asbestos fibers, hair felt and the like. The exposed foraminous member 34 preferably should be so perforated that the sounds will pass through it and be absorbed by absorber 38 in accordance with the principles of the Norris Patent No. 1,726,500.

Fig. 3 shows another construction in which sound absorbing material is used. In the particular construction shown, the sound to be absorbed is not that which originates in the room or other space to be ventilated but which originates in the air inlet and may be due to extraneous noises or those resulting from the movement of the fan and usually called fan-noises. The plenum chamber 40 is formed by the inner perforated sheet-like member or restriction member 42 and the ceiling or roof 44 and side walls 46 and 48. The inner perforate member 42 is spaced from the outer perforate member D by suitable supports 54. Outer member 50 forms the ceiling and is visible to the occupants of the room. Sound absorbing material 52, which also insulates the plenum chamber against outside heat and cold, is glued, nailed, or otherwise fastened to the roof or ceiling 44 and may be used to cover the side walls 46 and 48, if that is necessary. In this construction some of the noises originating in the room to be ventilated may be absorbed by the sound absorbing material 52, the amount of absorption depending upon the size and spacings of the perforations in the foraminous sheets 42 and 5U. The effect of the spacing of the holes on sound absorption is explained in the Norris Patent No. 1,726,500.

The construction shown in the drawings and described are illustrative of the invention, but the invention is not limited to these specific structures.

I claim:

1. In a Ventilating system, the combination with a wall or ceiling of the space to be ventilated, of an extended sheet-form, apertured member spaced interiorly from said wall or ceiling, a second apertured sheetform restriction member of substantially air-impervious material between said wall or ceiling and said first member and spaced from said first member and forming a plenum chamber with said wall or ceiling, and means for introducing Ventilating air into said plenum chamber, said restriction member having distributed openings therein having a total area comprising from 0.3 percent to 5.0 percent of the total area thereof, the construction being such that a slight pressure is maintained in said plenum chamber when said Ventilating system is in operation.

2. In a Ventilating system, the combination with a wall or ceiling of the space to be ventilated, of an extended sheet-form, apertured member spaced interiorly from said wall or ceiling, a second apertured sheet-form restriction member of substantially air-impervious material between said wall or ceiling and said first member in spaced relation to said first member and forming a plenum chamber with said wall or ceiling, and means for introducing Ventilating air into said plenum chamber, said restriction member having distributed openings therein of such total area that an air pressure of 0.001 inch of water to 0.300 inch of water is maintained in said plenum chamber when said Ventilating system is in operation, the air velocty in said room beyond said first apertured member being 1/2 foot to 25 feet a minute.

3. In a Ventilating system for a vehicle, an apertured partition in spaced substantially parallel relation to the roof of said vehicle extending substantially the length of said vehicle and forming a chamber superjacent the interior thereof, means for controlling the flow of Ventilating air through the apertures in said partition comprising a plurality of panels of limited perviousness arranged in a plane within said chamber, the totality of said panels being substantially coextensive with said apertured partition, at least a portion of said panels being spaced apart to permit the flow of air therebetween, and means for introducing Ventilating air into the space between said plane and said roof, the spacing apart of said panels at different zones of said plane Varying to permit the flow of air through the openings between said spaced apart panels in predetermined quantities.

4. In a Ventilating system for a Vehicle, an apertured partition in spaced substantially parallel relation to the roof of said vehicle extending substantially the length of said Vehicle and forming a chamber superjacent the interior thereof, means for controlling the ow of Ventilating air through the apertures in said partition comprising a plurality of apertured panels arranged in a plane within said chamber, the totality of said panels being substantially co-extensiVe with said apertured partition, and means for introducing the Ventilating air into the space between said plane and said roof at one end of said Vehicle, a number of said panels in the portion of said plane remote from said end of said vehicle at which air is introduced into the space between said plane and said roof being spaced apart to permit the flow of air therebetween, the spacing apart of said panels in said portion of said plane being such as to permit the flow of air through the openings between said spaced apart panels in predetermined quantities.

5. In a Ventilating system, the combination with a wall or ceiling of the space to be Ventilated, of an extended sheet-form, apertured member spaced interiorly from said wall or ceiling, a second apertured sheet-form, restriction member of substantially air-impervious material between said wall or ceiling and said rst member in spaced relation to said first member and forming a plenum chamber with said wall or ceiling, means for introducing Ventilating air into said plenum chamber, said restriction member having distributed openings therein of such total area that a slight pressure is maintained in said plenum chamber when said Ventilating system is in operation, whereby the air passes through all of said openings of said restriction member at substantially the same Velocity, and a facing of sound-absorbing material arranged on said wall or ceiling.

6. In a Ventilating system, the combination with a wall or ceiling of the space to be Ventilated, of an extended sheet-form, apertured member spaced interiorly from said wall or ceiling, a second apertured sheet-form restriction member of substantially air-impervious material between said wall or ceiling and said rst member in spaced relation to said rst member. and forming a plenum chamber with said wall or ceiling, means for introducing Ventilating air into said plenum chamber, said restriction member having distributed openings therein of such total area that a slight pressure is maintained in said plenum chamber when said Ventilating system is in opt eration, whereby the air passes through all of said openings of said restriction member at nearly the same velocity, and sound absorbing material arranged on said restriction member on the surface opposite said plenum chamber.

RALPH FORBUSH NORRIS. 

